Abstract

We report on the pressure dependence of the threshold current in and quantum-well lasers measured at low temperatures. It was found that the threshold current of both devices slowly increases with increasing pressure (i.e., increasing band gap) at consistent with the calculated variation of the radiative current. In contrast, at room temperature we observed a reduction of the threshold current with increasing pressure. Our low-temperature,high-pressure data confirm the results of previous atmospheric pressuremeasurements on the same devices which indicated a transition in the dominant recombination mechanism from radiative to Auger as the device temperature is increased from to .

The authors would like to thank Mr. G. J. Strudwick and Mr. D. McConville for their technical help with this work. This work was supported by the Engineering and Physical Sciences Research Council (EPSRC) (UK).